This invention relates to the field of geometrical angular measuring to provide saw angular settings where parts, particularly in carpentry work, are to be joined.
In carpentry work, a common problem in the cutting of trim, molding, shelves and the like, is that many times the angles are not what they are suppose to be. Especially is this true where there is an angular junction. That is, if an angle is suppose to be 90xc2x0, very often it is not. If the carpenter assumes it is 90, when it is, for example 87xc2x0, then when he cuts the connecting trim, etc., at 45xc2x0 there will be an imperfect fit. Very often the carpenter has no convenient way to obtain the exact angle to provide the angular setting of a table or miter saw. Thus the carpenter usually ends up wasting much time, cutting and trying until the pieces fit. Any thing less than an experienced craftsman ends up with misfitting junctions.
There are many patented angle measuring devices, such as the well known xe2x80x9ccarpenter""s squarexe2x80x9d and those shown in U.S. Pat. Nos. 101,477; 726,973; 2,607,121; 3,009,250; 3,070,887; 4,481,720; 4,744,152; 4,901,444; 5,117,560; 5,187,877; 5,189,804; 5,539,991; and 5,669,149. U.S. Pat. No. 5,117,550 provides a means to obtain a reading for the setting of the Miter saw. However it is a two piece device, one for measuring the angle, the second, a protractor, for reading the actual angle and the required saw angle. The one used to measure the angle is placed, and bolted, into position upon the protractor. Such a device is cumbersome to use and, being two pieces, not always handy or lost on the job.
It is a primary object of this invention to provide a device for measuring the true corner angles in trim and other carpentry uses.
It is another object of this invention to provide a device for measuring the true angle in trim and other carpentry uses which provides information and/or read-out indicia of the proper sawing angle for trim, molding, shelving, etc.
It is another object of this invention to provide a device for measuring the true angle in preparing trim and other carpentry uses which provides inside and outside corner saw angle readings.
This invention is a pivotally connected two piece angular measuring device that will give the carpenter, no matter of what experience, the capabilities of measuring angles that have to be taken from a surface, an edge, or a corner, for a subsequent operation. The device has a scale that reads not only the whole or true actual angle, the bisected angle, andlor the actual saw angle. As such the device of this invention provides easy determination of a miter angle and setting for a miter saw. The device is particularly adaptable and easy to use for those working with door facing molding, wall trim, chair rail, cove molding, crown molding, book shelves, baseboard, and other joinery needs. It is also adaptable for other non-carpentry work and installation, such as plumbing, electrical conduit, etc, or anywhere that angular measurements are needed to achieve high standards of accuracy and precision.
In particular the preferred device of this invention will provide saw, such as miter saw, angle settings for trim carpentry work. The device comprises two pivotally connected arms. The first arm has an outer straight edge and a face upon which are first and second angular scale markings. These scales comprise radial markings on a segment of a circle. The first angular scale representing true angle of the position of the two outer straight edges relative to each other. The second angular scale represents the 180xc2x0 complement of the true angle.
The second arm has an outer straight edge and a face upon which is a pointer means and angular scale markings that coincide with the angular scales on the first arm. The pivot point of the two arms defines the center point of the of the first and second radial scale markings. Means are provided to indicate to the carpenter the saw settings to achieve a properly fitted piece of trim. This may come in the form of actual indicia on the face of the first arm, or by way of calculation.